[BC] Aluminum and magnetic/electric currents

[Lamar Owen]

On Wednesday 01 February 2006 09:44, WFIFeng at aol.com wrote:
> In a message dated 02/01/2006 09:10:33 AM Eastern Standard Time,
> kzerocx at rapidcity.net writes:
> >  I presume that the magnets induce eddy currents in
> >  the moving paddle and I squared R losses convert the motion to heat. 
> > Also, isn't the rotating disk in a watt-hour meter made of aluminum?

> I don't know about the watt-hour meter, but we bought a gadget to convert a
> standard bicycle into a stationary excercycle, and it uses an aluminum
> plate between magnets to provide a smooth drag. Adjusting the spacing
> between the magnets and the disc adjusts the amount of drag. That thing
> gets *quite warm* after a rigorous workout. It would be cool to harness
> that energy to charge a battery or something. <g>

You can.  But you need extremely low resistance sliding contacts on the rim of 
the disc (opposing sides).  The current generated is DC, very low voltage, 
and very high current capacity.

I have a book that gives the technical name for this, but the name escapes me 
right now; will look it up.  The neat thing is that, if you align the axis of 
the disc with the Earth's magnetic poles, you can get the same generator 
capacity.
-- 
Lamar Owen
Director of Information Technology
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC  28772
(828)862-5554
www.pari.edu